1. Field of the Invention
The invention relates to a process for decarboxylating carboxylic acids.
2. Discussion of the Background
The decarboxylation of amino acids is a commonly used process for preparing amino compounds. The resulting amino compounds are in turn starting compounds for numerous industrial intermediates and active pharmaceutical ingredients.
The reaction mechanism for a decarboxylation of amino acids in the presence of ketones as a catalyst is described by Chatelus in Bull. Soc. Chim. Fr., 1964, 2523-2532:

Hashimoto et al. describe, in Chemistry Letters (1986) 893-896, the decarboxylation of α-amino acids using 2-cyclohexen-1-one as a catalyst.
JP 4010452 B also describes a process for decarboxylating amino acids, wherein the amino acid is initially charged in the cyclohexanol solvent and the 2-cyclohexen-1-one catalyst is added.
The processes described in the related art use amino acids as a pure substance. However, these amino acids are frequently available commercially only as aqueous solutions. The recovery of the pure substance from the aqueous solution may, in the individual case, be extremely difficult and laborious. Moreover, the related art processes are batchwise processes.